This invention relates to novel tobacco products, novel tobacco flavoring compositions, and processes for producing same, and has for an object the provision of a composition and process for improving the flavor and aroma of tobacco and tobacco smoke.
It is well known in the tobacco art that the flavor and aroma of the tobacco product and the smoke from the tobacco are very important considerations insofar as the ultimate consumer is concerned. Considerable efforts have been and are being exerted by the manufacturers of tobacco products to provide a product that will be both acceptable to the consumer, particularly as regards flavor and aroma characteristics, on smoking. Notes having Turkish-like characteristics as well as aromatic, sweet, sour, bitter, fruity, green and strawberry notes are desirable in tobacco flavoring compositions.
U.S. Pat. No. 3,499,769 issued on Mar. 10, 1970, discloses processes for imparting a fruity flavor (particularly strawberry flavor) to foods by adding a small amount of 2-methyl-4- pentenoic acid to the foodstuff. In U.S. Pat. No. 3,499,769 it is emphasized that the basic nuance imparted by the 2-methyl-2-pentenoic acid is a "berry" flavor.
Quite unexpectedly, the 2-methyl-4-pentenoic acid and esters thereof of the instant invention have properties different in kind from the 2-methyl-2-pentenoic acid of U.S. Pat. No. 3,499,769 which is only fruity and strawberry-like and does not have the tobacco flavor enhancing qualities of the 2-methyl-4-pentenoic acid and esters thereof of the instant invention.
Arctander, "Perfume and Flavor Chemicals", 1969 discloses the use in perfume compositions and flavors of 4-pentenoic acid, thus:
". . . only rarely used in perfume compositions mainly on fruity bases and certain artificial essential oils. PA1 It finds use in flavors on account of its sour-caramellic taste, pleasant at levels below 10 ppm, and including an almost sweet aftertaste. Higher concentrations have acrid taste and repulsively acid odor, pungent and irritating. PA1 Traces, equivalent to 1 to 5 ppm, are used in imitation butter flavor and in various fruit flavor complexes, e.g., apple, pineapple, apricot and strawberry." PA1 "Spicy-rooty, sweet-sour herbaceous odor of moderate tenacity." PA1 a. First reacting 1,1,1-triethoxypropane with 2-propanol-1 in the presence of a phosphoric acid catalyst to form ethyl-2-methyl-4-pentenoate. The reaction temperature range is 100.degree.-225.degree. C with a range of 140.degree.-180.degree. C being preferred. The mole ratio of reactants preferred is 1:1, with a large excess of 2-propanol-1 undesirable and a large excess of triethoxypropane being uneconomical. The reaction time is inversely dependent upon the temperature of reaction. Thus, for example, where the temperature range of reaction is 165.degree.-185.degree. C, the reaction time is approximately three (3) hours. As stated, supra, the reaction product, ethyl-2-methyl-4-pentenoate may be used as is, or it may further be reacted as in step (b) set forth infra; but in any event, the reaction product is "worked-up" by first neutralizing the acid catalyst, the phosphoric acid, using base (e.g., sodium bicarbonate) and then fractionally distilling the reaction product.
At Volume II, No. 2452. Arctander also discloses the use of trans-2 -methyl-2-butenoic acid (tiglic acid) at Vol. II, No. 2949 in perfumery:
and the use of cis-2-methyl-2-butenoic acid (angelic acid) and alkyl esters thereof in perfumes and flavors at Vol. I, No. 238.
The alkenoic acids and esters thereof of the prior art are considered to be different in kind from the 2-methyl-4-pentenoic acid and C.sub.2 -C.sub.6 alkyl esters thereof of the instant invention insofar as their organoleptic properties are concerned.